To find the odds in favor of an event, we need to compare the probability that the event will happen to the probability that it will not happen.

Given:

• The probability of rain tomorrow is 30%, or $\frac{30}{100}$.
• The probability of no rain is $1 - 0.30 = 0.70$, or $\frac{70}{100}$.

Now, the odds in favor of an event are expressed as the ratio of the probability of the event happening to the probability of it not happening:

$\text{Odds in favor of rain} = \frac{\text{Probability of rain}}{\text{Probability of no rain}} = \frac{30}{70} = \frac{3}{7}$

Therefore, the odds in favor of it raining tomorrow are 3:7.

Answer: 3:7

Would you like to dive deeper into how probability and odds work, or do you have any further questions?

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Here are 8 related questions:

1. What are the odds against it raining tomorrow?
2. How do you calculate odds when given percentages?
3. What are the odds in favor of an event with a 50% chance?
4. How are probability and odds different?
5. If the probability of rain increases to 40%, what are the new odds in favor?
6. What are the odds of flipping heads on a fair coin?
7. How would you express odds if the chance of an event happening is 80%?
8. Can odds ever be expressed as decimals?

Tip: Odds are a ratio comparing the likelihood of an event to its complement, while probability is a proportion out of the total outcomes.